1. Field of the Invention
The invention relates to an exhaust system structure and method for manufacture comprising two or more silencers which are placed in series and are each provided with a tubular section, the edges of which are in each case attached to a transverse plate which marks the end of the section in question, and each tubular section is provided with sound-damping internal parts. Two tubular sections with different cross-sections are mounted one behind the other, making use of a transverse plate, the external dimensions of which are related to the cross-sectional dimensions of the tubular section with the largest cross-section. The transverse plate is provided with an opening, the dimensions of which are related to the cross-sectional dimensions of the tubular section with the smallest cross-section.
2. Description of the Related Art
An exhaust system of this kind is known from German Laid-open Specification DE 19514829 A1. The exhaust system described in that document is intended to be used in a motorcycle and comprises a cylindrical section with a relatively large cross-section, in which sound-damping internal parts are arranged, and a cylindrical section with a relatively small cross-section, in which sound-damping internal parts are also arranged. The two sections are connected to one another via a transverse plate which is attached to the edges of the two sections by means of welding or soldering. In order to be adapted to the space available, the transverse plate is not planar but rather shaped so as to be able to accommodate the entire combination within the desired space.
Forming joints between various sections and the transverse plates employed by means of welding or soldering is regarded as disadvantageous. If welded or soldered joints are to be used, it is necessary for the plate materials employed to have a certain minimum thickness in order, on the one hand, to minimize the occurrence of mechanical stresses and deformations in the system and, on the other hand, to avoid the parts to be welded (soldered) simply burning away and consequently not being welded.
It should be noted that various publications are already known from the prior art in which use is made of seamed roll joints at similar locations.
U.S. Pat. No. 5,559,308 describes a single silencer provided with a tubular section which is closed off at both ends by a transverse plate. The transverse plates are attached to the tube section by means of seamed roll joints. A pipe stub to which further pipes can be connected is mounted in each of the transverse plates by means of an S-shaped deformation of the plate. This document deals with a single silencer, not with a combination of two or more silencers.
FR 2,457,969 describes a structure in which the outer edge of a transverse plate is fixed to the edge of a tubular section by means of seamed roll joints, while a pipe is fixed in an opening in the transverse plate by means of a so-called ridge lock connection. A ridge lock connection is less durable than a real seamed roll joint. Furthermore, this is clearly not a combination of two silencers.
EP 0,252,373 describes a single silencer provided with a tubular section which is closed off at both ends by a transverse plate. The transverse plates are attached to the tube section by means of seamed roll joints. A pipe is fitted in each of the transverse plates by means of a ridge lock connection. This document again deals with a single silencer, and not with a combination of two or more silencers.